Magnet based electrical machine are well know in the art, and operate on the principle that electrical current generates electromagnetic flux and vise versa. In most such machines, a rotor comprising permanent magnets is configured for revolving within an electromagnetic field generated by a plurality of electromagnetic units associates with a coil through which electricity is passed.
One such example is an electrical machine described the applicant in WO10089734 which discloses an electrical machine comprising a stator and a rotor rotatable relative to the stator with an air gap therebetween is disclosed. The stator is provided with a first plurality of sources of magnetic field which is equally spaced in a circumferential configuration over the stator. The rotor is provided with a second plurality of sources of magnetic field which is equally spaced in a circumferential configuration over the rotor. The magnetic sources of at least one plurality are electromagnets; each electromagnet comprises at least one magnet coil resting on a magnet conductor. The magnetic conductor comprises at least one member made of magnetically isotropic and/or anisotropic materials.
Different electrical machines utilize various electromagnetic units, each with its own geometry and assembly method.
One example is U.S. Pat. No. 7,851,965 which disclosed transverse and/or commutated flux machines and components thereof, and methods of making and using the same. Certain rotors for use in transverse and commutated flux machines may be formed to facilitate a “many to many” flux switch configuration between flux concentrating stator portions having opposite polarities. Other rotors may be formed from a first material, and contain flux switches formed from a second material. Yet other rotors may be machined, pressed, stamped, folded, and/or otherwise mechanically formed. Via use of such rotors, transverse and/or commutated flux machines can achieve improved performance, efficiency, and/or be sized or otherwise configured for various applications
Another example is WO0237651 which discloses linear motor and a method of producing the linear motor are provided to reduce a leak magnetic flux flowing between an armature and a moving element to reduce a one-direction magnetic attraction force generated between the armature and the moving element. The linear motor includes the armature having a core formed of a magnetic body and a winding wound around the core, and the moving element supported so as for the moving element to move relatively to the armature via a gap, magnetic pole teeth disposed above and below the moving element, disposed at predetermined pitches along a moving direction of the moving element and disposed opposite to each other via the moving element, and a winding for exciting the magnetic pole teeth such that adjacent and opposite magnetic pole teeth have different magnetic poles, and the moving element is reciprocated relatively to the armature by exciting the winding according to a predetermined control circuit
Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.